Oscillation of a graphene flake on an undulated substrate with amplitude gradient

The oscillation of a graphene flake on a substrate with undulated surface is investigated by classical molecular dynamics simulation. The gradient in amplitude of the undulation is found to provide the driving force for the motion of the graphene flake, which slides on top of a graphene layer that well conforms to the substrate. The oscillatory motion of the flake can be well described by the equation of motion of a damped oscillator, with damping factor corresponding to the friction coefficient between the flake and the graphene layer on which it glides. When the amplitude gradient increases, the oscillation frequency increases as well. The shape of the graphene flake is found to have a strong influence on friction, as some geometries promote in-plane rotation. The results in the present study point to an alternative approach to transport or manipulation of nanosized objects.